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目的 结合遥感技术和地面生态学调查数据区分钉螺孳生地并监测其变化。 方法 从鄱阳湖共选择10 0个调查点 ,75个为从鄱阳湖 5 74块草洲中随机抽取。根据历史调查 (1982～ 1984 ) ,其中 5 0个有螺 ,2 5个无螺 ,另2 5个为非钉螺孳生地调查点。将每个调查点 (面积 10 0 0 0 m2 )分成 10 0格 ,从中随机抽取 2 0格 ,在每格的中央置钉螺调查框 (4m2 ) ,收集框内所有钉螺。收集与地面调查同期的 TM卫片。采用非监督分类法对卫片进行分类并结合地面调查结果区分钉螺孳生地。 结果 分类的敏感性和特异性分别为 90 .0 %～ 95 .6 %和 6 1.1%～ 6 8.6 %。 1999～ 2 0 0 0年 ,鄱阳湖区估算的钉螺孳生地面积变幅为 6 2 3.4～ 76 2 .8km2。 结论 钉螺孳生地与植被覆盖的区域有关 ,卫片分类能用于区分钉螺孳生地确定其范围并监测其随关键因素的波动而造成的变化。
Objective To distinguish snail breeding place and monitor its change by combining the remote sensing technology with the surface ecological survey data. Methods A total of 10 0 investigation points were selected from Poyang Lake and 75 were randomly selected from 5 74 grassland in Poyang Lake. According to historical surveys (1982 ~ 1984), 50 were snails and 25 were non-snails, and another 25 were non-snail breeding sites. Each survey site (area 10 000 m2) was divided into 100 grids and randomly selected from 20 grids. A snail check box (4 m2) was placed in the center of each grid to collect all the snails in the box. Collect TM tablets for the same period as the ground survey. The unsupervised taxonomy was used to classify the hygienic patches and to distinguish the snail breeding sites based on the ground survey results. The sensitivity and specificity of the classification were 90.0% -95.6% and 61.1% -6.6%, respectively. Estimated areas of snail breeding in Poyang Lake area ranged from 62.4 to 76.2.8 km2 from 1999 to 2000. Conclusion Siphon breeding area is related to the area covered by vegetation. Slice classification can be used to distinguish snail breeding area from its range and to monitor changes with key factors.